Mining prop



L. F. GERDETZ MINING PROP July 22, 1930. Y

Filed sept. 14, 192#v Patented July 22, 1930.

Umrsssiarss PATENT "oFFlcEg MINING 12'1201D Appncatin filed september 14, 1927; serial No. 219,491.

This invention relates to an improvement in mining props.V Y*

The invention relates to an adjustable safety steel prop, which is designed to re place the use ot wooden supports (props) etc. in coal and metal mines, tunnel constructions and other underground operations. The objects of the invention are tirst, toprovide a steel prop which absorbs weight gradl@ ually and gives-under pressure of rootl or overburden; second, 'to oer resistance to pressure and weight by friction and compression of certain of its members; and third, to, when necessary, be made to collapse from .15 under the weight and be removed trom a sate distance ,in order to be used over and overlagain, l y The invention resides in the structure of the prop, in which-a lower H-shaped supporting `member is-adapted to restA in the lower portion of the -mine lor other kunderground passage and have an upper wedgeshaped member slidably connected therewith. A slot is formed in the H-beam to 25 receive `a bolt which isfconnected with the wedge-shaped upper member, to regulate the sliding movement'thereot. l Suitable locking mechanism is pivotally associated with the members in order to regulate .the positions of the two or Ato release the wedge-shaped upper supporting member to allow it to tall `whenever desired. i j f Y The advantage of making this locking mechanism pivoted is that it'ymay be opere ated from a suitable and safe distance. thus eliminating any danger to the lives ot the miners when releasing' the'p'rop.

In the accompanying ,drawings Fig. 1 is the front view of the prop when extended; Y

Fig. 2 is a vertical section ot the prop on the line A-B in Fig. 1;

Fig.` 3 is a horizontal section ot the prop on theline G-D in Fig. 1;

Fig. #l is a side view of the prop when collapsed; and

Fig. 5 shows a slight modiication.

The construction of the prop includes a lower member, being an H-shaped steel column 1. This column is provided with a slot plates 6 by one of the steel pins 2 cut'into its web to allow a bolt 3 oit the upper member to slide up and down therein. A foot shoe l is'riveted to the flanges of the column 1. Four steel plates 5 riveted to the flanges provide a recess for side plates 6 of the locking mechanism to `beheld in place and slide laterallytherebetween.

The upper member consists ofv two channel-shaped steel columns 7 riveted together web to vweb with a spacer 8 therebetween, tov allow them to slide up or down on each side ot the web ot theH-shaped member 1. The two channel-shaped steel columns .7 are held together at their lower ends by the bolt 3, which in turn is provided with a sleeve 9 in order to hold the channel shaped steel column `7 in position and asuitable distance'apart.

The bolt 3 and sleevel `9 travel through the slot 2 when the upper member is either raised or lowered. f-

Mounted between `th'ejflanges of the two steel channels 7 aretwohardwood fillers 10 covered by steel liners 11 and formingan inclined wedge. The hardwood fillers 10 and steel liners 11 are held in place by, a

rivet 12 and the bolt 3 extending therefthrough. A steel cap 13 is riveted to the steell channels 7' on top of the column.

The locking mechanism lconsists of two vsteel side plates 6 held together onboth ends by two bolts or pins 14. The side plates 6 rest on and can move laterally relativeto the iianges of the H-beam in the recesses formed between the tour plates 5. Trip block 15 is located on the front side of theV prop and is held in place between the side 14, on which it can revolve. When in locked position, the trip block 15 bearsagainst one'side of the wedge-shaped surface of the upper member. The handle of the trip bloclr is provided with a hole 15 through which a rope or chain (not shown) may be fastened when it is desired to trip the block from a safe distance and cause the prop to collapse and be removed from under dangerous'root or tall.

A toggle-17 ist-located on the back side of the prop and is held in place between the side plates 6 by one ofthe steel Vpins 111," on which it can revolve. It can `tit itself snug CIC against various shapes of wedges inserted in between itself and the wedge shaped part of the upper member. ihen in locked position, the toggle 17 bears against the wooden wedge 18 and through it against the side of the wedge shaped. part of the upper member..

When the adjustable safety prop is set in position and locked, the tendencies `of the wedge-shaped member is to settle or give under weight or pressure. it then simulates on a larger scale the give of a wooden prop under similar conditions, without however being` exposed to the disastrous results Vwhich invariably occur to the latter, when bearing under excessive pressure, it fails for want of sufficient resiliency and, as such, constitutes a menace to the lives of men engaged in mining. it best, in such cases a wooden prop is a total loss in addition to costly and dangerous falls and caves caused by its failure. The settlement or give of the adjustable safety steel prop is accomplished at the eX- pense of the wooden wedge 18 which is being gradually compressed as the wedge shaped upper member descends. An ever increasing resistance to the settlement or give of the prop is offered in addition to the compression of the wedge 18, by the friction of webs of. the

upper and lower members against each other.

The alignmentof the upper and lower members of the props in respect to each other allows an even distribution of stre s and prevents any distortion of the prop when under pressure or weight.

The adjustable safety prop is designed to be manufactured in various lengths. each adjustable to a certain extent to heights of coal seams, etc.

It might be mentioned that the iilles l0 are preferred for lightness. but it is perfect-- ly obvious that solid metal strips .mic-ht be employed in lieu of the T.vooden fille... in which event the liners ll would be entirely omitted.

It is also obvious that the channel-irons as shown at 7 might be turned in the opposite direction as illustrated at 7n in Fig. 5, in which event no filler-strips such as l0 would be used.

l. A mining prop comprising an lai-shaped lower member having slotted web.y an approximatery wedge-shaped upper member having portions thereof embracing the web of the H-shaped lower member, and ccnnected together through the slot. a yieldable block in position to bear against one side of the wedge-shaped upper member, and a pivotally mounted .locking member arranged on and adapted to bear against the opposite side of the upper member.

2. A mining prop comprising an H-shaped lower member having a slotted web, an approximately wedge-shaped upper member having portions "hereof embracing' the web of the H-shaped lower member, and connected together through the slot, a relatively flat faced member carried by the lower member, a compressible block interposed between the flat faced member and the wedge-shaped member, normally tending to hold the members in set positions and to allow relative longitudinal movement thereof under substantial pressure, and a pivotally mounted locking member arranged on and adapted to bear against the opposite side of thewedgeshaped member from the compressible block for releasing the members.

3. A mining prop comprising members connected together for relative longitudinal movement, one of said members having a slotted web, the other member being approximately wedge-shaped and having portions thereof embracing the web of the first-mentioned member, and connected together through the slot, and a block in position to bear against one side of the wedge-shaped member.

il. A mining prop comprising members con nected together for relative longitudinal movement, one of said members having a slotted web, the other member being approximately wedgeshaped and having portions thereof embracing the web of the irst-men tioned member and connected together through the slot, a yieldable blocl in position to bear against one side of the wedge-shaped member, and locking means ar 1anged on and adapted to bear against the opposite side of the wedge-shaped member.

5. A mining prop having upper and lower members slidably connected together, said upper member being approximately wedgeshaped, a compressible block acting on the wedge-shaped member to be compressed upon a subsidence of the upper member, and a pivotally mounted releasable member to release the pressure on the prop.

6. mining prop having upper and lower members slidably connected together, said upper member being approximately wedgeshaped, side pla-tes slidable transversely of and connected with the lower member, a compressible block mounted between said plates and held thereby to act on one side of the wedge-shaped member, to be compressed upon a subsidence thereof, and an upwardly turned locking member pivotally connected with the plates in position to act on the opposite side of the wedge-shaped member and to release the pressure on the prop.

In testimony whereof I affix my signature.

LOUIS F. GERDETZ. 

